Added the order mode (BOTTOM by default, and TOP by specify app:stack_order_top="true")

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.0.0-beta5'
+        classpath 'com.android.tools.build:gradle:2.1.2'
         classpath 'com.novoda:bintray-release:0.3.4'
     }
 }

library/src/main/java/link/fls/swipestack/SwipeStack.java

@@ -44,6 +44,7 @@ public class SwipeStack extends ViewGroup {
     public static final float DEFAULT_SWIPE_OPACITY = 1f;
     public static final float DEFAULT_SCALE_FACTOR = 1f;
     public static final boolean DEFAULT_DISABLE_HW_ACCELERATION = true;
+    public static final boolean DEFAULT_STACK_ORDER_TOP = false;
 
     private static final String KEY_SUPER_STATE = "superState";
     private static final String KEY_CURRENT_INDEX = "currentIndex";
@@ -61,6 +62,7 @@ public class SwipeStack extends ViewGroup {
     private float mSwipeOpacity;
     private float mScaleFactor;
     private boolean mDisableHwAcceleration;
+    private boolean mStackOrderTop;
     private boolean mIsFirstLayout = true;
 
     private View mTopView;
@@ -109,6 +111,9 @@ private void readAttributes(AttributeSet attributeSet) {
             mDisableHwAcceleration =
                     attrs.getBoolean(R.styleable.SwipeStack_disable_hw_acceleration,
                             DEFAULT_DISABLE_HW_ACCELERATION);
+            mStackOrderTop =
+                    attrs.getBoolean(R.styleable.SwipeStack_stack_order_top,
+                            DEFAULT_STACK_ORDER_TOP);
         } finally {
             attrs.recycle();
         }
@@ -222,7 +227,7 @@ private void reorderItems() {
 
             int distanceToViewAbove = (topViewIndex * mViewSpacing) - (x * mViewSpacing);
             int newPositionX = (getWidth() - childView.getMeasuredWidth()) / 2;
-            int newPositionY = distanceToViewAbove + getPaddingTop();
+            int newPositionY = mStackOrderTop ? -distanceToViewAbove + getPaddingTop() : distanceToViewAbove + getPaddingTop();
 
             childView.layout(
                     newPositionX,

library/src/main/res/values/attrs.xml

@@ -14,5 +14,6 @@
         <attr name="swipe_opacity" format="float"/>
         <attr name="scale_factor" format="float"/>
         <attr name="disable_hw_acceleration" format="boolean"/>
+        <attr name="stack_order_top" format="boolean" />
     </declare-styleable>
 </resources>

sample/src/main/res/layout/activity_main.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -15,7 +14,7 @@
         android:layout_height="wrap_content"
         android:layout_alignParentBottom="true"
         android:layout_alignParentLeft="true"
-        android:text="@string/swipe_left"/>
+        android:text="@string/swipe_left" />
 
     <Button
         android:id="@+id/buttonSwipeRight"
@@ -24,16 +23,17 @@
         android:layout_height="wrap_content"
         android:layout_alignParentBottom="true"
         android:layout_alignParentRight="true"
-        android:text="@string/swipe_right"/>
+        android:text="@string/swipe_right" />
 
     <link.fls.swipestack.SwipeStack
         android:id="@+id/swipeStack"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_above="@+id/buttonSwipeLeft"
         android:padding="@dimen/padding_swipestack"
+        app:stack_order_top="true"
         app:stack_rotation="10"
-        app:stack_size="3"/>
+        app:stack_size="3" />
 
     <android.support.design.widget.CoordinatorLayout
         android:layout_width="match_parent"
@@ -46,7 +46,7 @@
             android:layout_gravity="bottom|center"
             android:layout_margin="@dimen/margin_fab"
             android:src="@drawable/ic_content_add"
-            app:fabSize="normal"/>
+            app:fabSize="normal" />
 
     </android.support.design.widget.CoordinatorLayout>